Writing stylus

ABSTRACT

A stylus for an electrographic position location apparatus is disclosed. In one embodiment, the stylus includes a writing element that is retractable. The stylus may have a proximal end and a distal end. A conductive annular structure may be at the proximal end of the stylus.

BACKGROUND OF THE INVENTION

This application is a continuation application of U.S. patentapplication Ser. No. 10/457,981, filed on Jun. 9, 2003 now U.S. Pat. No.7,068,262, which is herein incorporated by reference in its entirety forall purposes.

A number of electrographic position location apparatuses have beendescribed. One such apparatus is described in U.S. Pat. No. 5,485,176 toOhara et al. The apparatus that is described in Ohara et al. includes alower base portion and a pivotal back structure upon which a book rests.The back structure contains electronics. A video monitor is incommunication with electronics in the back structure. A stylus is usedto select images on open pages in the book and some response is thenseen on the video monitor.

While the apparatus described in Ohara et al. is useful, a number ofimprovements can be made. For example, the apparatus described in Oharaet al. does not use a writing element. Writing is necessary for learninghow to write letters and numbers. Writing is also an important tool forteaching a child a complex subject such as math. For example, manystudents cannot learn math without writing down equations and numbers.Accordingly, it would be difficult to teach someone a subject such asmath and writing using the apparatus described in Ohara et al.

Students have learned about subjects such as math using traditionallearning tools such as books, paper, pencils, and personalizedinstruction. While such learning tools are effective, they are not fun,engaging, or interactive.

Accordingly, it would be desirable if traditional learning tools such aspencils, pens, paper, and/or books could be used in a more interactiveway that can be entertaining, educational and engaging for students.

Embodiments of the invention address these and other problems.

SUMMARY OF THE INVENTION

Embodiments of the invention are directed to styluses for electrographicposition location apparatuses, electrographic position locationapparatuses, and methods for using the styluses and electrographicposition location apparatuses.

One embodiment of the invention is directed to a stylus for anelectrographic position location apparatus comprising a surface, thestylus comprising: (a) a distal end region; (b) a proximal end region;(c) a writing element including a first end portion proximate to thedistal end region and a second end portion proximate to the proximal endregion; and (d) a conductive annular structure having a continuous andsolid side surface at the distal end region of the stylus, wherein theconductive annular structure is around the first end portion of thewriting element, and wherein the conductive annular structure is adaptedto receive or transmit an electromagnetic signal when the stylus is overthe surface.

Another embodiment of the invention is directed to a stylus assemblycomprising: (a) a stylus comprising (i) a distal end region, (ii) aproximal end region, and (iii) a retractable writing element having afirst end portion proximate to the distal end region of the stylus and asecond end portion proximate to the proximal end region of the stylus;and (b) a cable coupled to the proximal end region of the stylus,wherein the cable comprises a conductor.

Another embodiment of the invention is directed to an electrographicposition location apparatus comprising: (a) a housing comprising asurface; (b) an antenna under the surface; (c) a processor coupled tothe antenna; (d) a stylus comprising (i) a distal end region, (ii) aproximal end region, (iii) a writing element including a first endportion proximate to the distal end region and a second end portionproximate to the proximal end region; and (iv) a conductive annularstructure having a continuous and solid side surface around at least thefirst end portion of the writing element, and being at the distal endregion of the stylus; (e) a cable coupling the proximal end region ofthe stylus to the housing; and (f) an output device coupled to theprocessor.

Another embodiment of the invention is directed to an electrographicposition location apparatus comprising: (a) a housing comprising asurface; (b) an antenna under the surface; (c) a processor coupled tothe antenna; (d) a stylus comprising (i) a distal end region, (ii) aproximal end region, and (iii) a retractable writing element including afirst end portion proximate to the distal end region and a second endportion proximate to the proximal end region; (e) a cable connecting theproximal end region of the stylus to the housing; and (f) an outputdevice coupled to the processor.

Another embodiment of the invention is directed to an electrographicposition location apparatus comprising: (a) a housing comprising asurface; (b) an antenna under the surface; (c) a processor coupled tothe antenna; (d) a stylus comprising (i) a distal end region, (ii) aproximal end region, and (iii) a conductive writing element including afirst end portion proximate to the distal end region and a second endportion proximate to the proximal end region; (e) a cable connecting theproximal end region of the stylus to the housing; and (f) an outputdevice coupled to the processor, wherein the antenna and the writingelement are in electrical communication during use.

Another embodiment of the invention is directed to a method comprising:(a) writing on a sheet in a print medium on a surface of a housing of anelectrographic position location apparatus using a stylus including aretractable writing element, wherein the writing element is in anextended position; (b) retracting the writing element into the stylus;and (c) selecting a print element in the print medium using the styluswhen the writing element in the stylus is in a retracted position.

These and other embodiments of the invention are described in furtherdetail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a stylus that includes a writingelement.

FIG. 2( a) shows an exploded view of a stylus.

FIG. 2( b) shows a mechanical pencil with a threaded cap.

FIG. 2( c) shows a cross-sectional view of a stylus according to anembodiment of the invention.

FIG. 3 shows a cross-sectional view of a mechanical pencil including anautomatic lead feeding mechanism.

FIG. 4 shows a cross-sectional of a stylus that includes a writingelement comprising ink. The writing element is in an extended position.

FIG. 5 shows a cross-section of a stylus that includes a writing elementcomprising ink. The writing element is in a retracted position.

FIGS. 6( a) and 6(b) show cross-sectional views of interacting cammembers in a stylus interacting to cause a writing element to be in anextended or a retracted position.

FIG. 7 shows a cross-section of a stylus over a book on a surface of ahousing of an electrographic position location apparatus.

FIGS. 8( a)–(b) are schematic illustrations of styluses, withoutconductive cones, wherein the styluses are positioned in different waysduring use.

FIGS. 8( c)–(d) are schematic illustrations of styluses, with conductivecones, wherein the styluses are positioned in different ways during use.

FIG. 9 is an exploded view of an electrographic position locationapparatus according to an embodiment of the invention.

FIG. 10 shows a pair of antennas with orthogonal conductive fingers.

FIG. 11 shows a block diagram of an electrographic position locationapparatus according to an embodiment of the invention.

These and other embodiments are described in further detail below in theDetailed Description with reference to the Figures.

DETAILED DESCRIPTION

One embodiment of the invention is directed to a stylus for use in anelectrographic position location apparatus. The stylus is capable ofwriting or marking on a writing surface. The writing surface may be asurface on a sheet of paper, a surface on an erasable sheet in a book,etc.

The electrographic position location apparatus comprises a housing witha surface. The sheet of paper, book, etc. can be on the surface of thehousing. As will be described in further detail below, the housing maycontain signal processing electronics including a microprocessor, atleast one antenna, and an output device. The at least one antenna can beunder a surface of the housing and may transmit an electromagneticsignal to a receiving antenna in the stylus above the surface. Thestylus may be tethered to the housing via a cable. The cableelectrically and mechanically couples the antenna in the stylus with thesignal processing electronics. When the antenna in the stylus receivesthe signal, the signal is then transmitted to the signal processingelectronics via the cable.

An output device may then produce an output (e.g., an audio or visualoutput) that corresponds to the location where the stylus was present.For example, the stylus may be positioned over the letter “A” on a sheetthat is on the surface of the housing and over a signal transmittingconductive finger under the surface. Signal processing electronicsidentify the particular signal being transmitted by the conductivefinger, and subsequently determine that the stylus is over the letter A.A corresponding output such as “A says Ahh” may then sound through anoutput device such as a speaker. In other embodiments, the output devicemay be a display like an LCD (liquid crystal display) or an LED (lightemitting diode).

In the electrographic position location apparatus described above, thestylus includes a receiving antenna that receives an electromagneticsignal from under a surface of a housing. However, in other embodiments,it is possible for the stylus to include a transmitting antenna whilethe antenna under the surface receives an electromagnetic signaltransmitted from the transmitting antenna. In this latter embodiment,the transmitting antenna in the stylus transmits a signal, which isreceived by one or more conductive fingers of one or more antennas underthe surface of a housing. Using the activated conductive fingers, signalprocessing electronics in the electrographic position location apparatuscan determine the location of the stylus and can provide an appropriateoutput for the particular location.

In some embodiments, the antenna in the stylus includes a conductiveannular structure that is at a distal end of the stylus and is around afirst end portion of the writing element. As will be explained infurther detail below, the conductive annular structure advantageouslyallows the stylus to receive the signal from the antenna under thesurface of the housing, regardless of the orientation of the stylus. Apreferred conductive annular structure is a conductive cone. Althoughconductive cones are described in detail below, it is understood thatany suitable conductive annular structure may be used in the stylus. Forexample, the conductive annular structure could alternatively be aconductive ring, a conductive cylinder, a stack of conductive hoops,etc. The conductive annular structure may comprise any suitableconductive material including copper or aluminum conductors, orconductive polymers.

The conductive annular structures preferably have a solid and continuousconductive side surface (e.g., like a solid cylinder or a solid cone),as opposed to, for example, a loop of wire which forms a discontinuousand non-solid surface in a conductive annular structure. Loops of wires,for example, can provide different output signals when the stylus is atan angle and when the stylus is perpendicular. It is desirable if thesame output signal is generated regardless of how the stylus is orientedabove a particular point on a surface.

The electrographic position location apparatuses according toembodiments of the invention may have any suitable end use. In preferredembodiments, the electronic position location apparatus is aneducational learning aid, which is adapted to teach the user about oneor more subjects. Exemplary subjects include math, reading, writing,geography, science, geometry, etc.

The electrographic position location apparatus may be in any suitableform. For example, in some embodiments, the electrographic positionlocation apparatus may include a housing in the form of a platform witha book on the platform. The stylus may be used to select words, symbols,or pictures in the book using the stylus, and/or may write in the bookusing the writing element in the stylus. In another embodiment, theelectrographic position location apparatus may be in the form of a globewith a base (both of which may form a housing), with a stylus coupled tothe base. In yet other embodiments, the electrographic position locationapparatus can be a graphics tablet type device that can automaticallytranslate drawings made using the stylus into an electronic image on adisplay screen.

The stylus in the electrographic position location apparatus comprises adistal end region and a proximal end region. As noted above, aconductive annular structure such as a conductive cone is at the distalend region of the stylus. The conductive annular structure is around afirst end portion of a writing element in the stylus. The conductiveannular structure and an electrical conductor in the stylus may form theantenna in the stylus. The conductor may be oriented generally coaxial(or parallel to) with the writing element. The antenna in the stylus maybe adapted to receive an electromagnetic signal from a transmittingantenna under the surface of the housing.

Any suitable writing element can be used in the stylus. Exemplarywriting elements may comprise some sort of erasable writing materialsuch as pencil lead or erasable ink. Specific examples of writingelements include pencils (mechanical and non-mechanical), wood pencils,chalk, automatic pencils, free-standing pencil leads, pens, pen refillcartridges, markers, crayons, etc. Preferably, the writing element is anautomatic pencil with an automatic lead feeding mechanism. A preferredwriting element is an automatic pencil sold under the tradename“Sensematic”, which is commercially available from Dixon Ticonderoga,Inc. Automatic pencils with automatic lead feeding mechanisms will bediscussed in further detail below.

The writing material (e.g., ink, pencil lead, etc.) that is used in thewriting element is preferably non-conductive. The use of anon-conductive writing material can reduce the likelihood that thewriting material will not interfere with the signal transmitting antennaunder the surface of the housing of the electrographic position locationapparatus. Also, a conductive writing material that is inside of thestylus may interfere with signals that are being transmitted by thestylus or received by the stylus. If a non-conductive writing materialis used, a separate ground shield need to be included for the writingelement in the stylus.

The writing element in the stylus may include a first end portionproximate to the distal end region of the stylus and a second endportion proximate to the proximal end region of the stylus. The firstend portion of the writing element corresponds to the portion of thewriting element that is used for writing.

In some embodiments, the writing element may be a retractable writingelement. Accordingly, the writing element in the stylus may or may notbe capable of writing, depending on the user's desire. The tip of thewriting element may be inside of the stylus when the stylus is in aretracted position. The tip of the writing element may extend outwardlyfrom the distal end of the stylus when the writing element is in anextended position so that the user may write with the stylus. The styluscan be capable of receiving (or transmitting) an electromagnetic signalwhen the writing element is either in an extended position or aretracted position.

FIG. 1 shows a stylus 200 according to an embodiment of the invention.The stylus 200 includes a distal end region 200(a) and a proximal endregion 200(b). The stylus 200 also includes a stylus housing 132. Aconductive grip 132(a) is on the stylus housing 132 and may include agripping surface so that the stylus 200 does not easily slip out of theuser's hand.

The distal end region 200(a) of the stylus 200 includes a writing tip158, which may correspond to a first end portion of a writing element(not shown in FIG. 1) that is inside of the stylus 200. The proximal endregion 200(b) of the stylus 200 includes a threaded cap 144 that isinsertable inside of a second end portion of the writing element insideof the housing 132. As will be explained in detail below, a user cancause the writing tip 158 to extend and retract by turning the threadedcap 144 clockwise or counterclockwise.

A cable 142 is shown in dotted lines and passes through a strain reliefelement 142(a) at the proximal end region 200(b) of the stylus 200. Thestain relief element 142(a) supports the cable 142 when the stylus 200is used. It reduces the strain on the cable 142 at the point where thecable 142 exits the housing 132. Together, the cable 142 and the stylus200 (and optionally other elements) may form a stylus assembly that canbe used in an electrographic position location apparatus.

The cable 142 can house at least two electrical conductors (e.g., wires)(not shown in FIG. 1). Preferably, the cable 142 is a co-axial cablewith a first conductor being a linear wire and a second conductor beingan annular wire to shield the inner linear wire. The first conductor maybe a conductor that electrically couples a conductive annular structureinside of the stylus housing 132 to signal processing electronics in theelectrographic position location apparatus. The second conductor mayelectrically couple the conductive grip 132(a) to a signal neutral pointsuch as ground.

It is desirable to ground the user by providing the conductive grip 132on the stylus housing 132. As noted above, electromagnetic signals canbe received from an antenna under a surface of the housing of theelectrographic position location apparatus. A receiving antenna instylus 200 can receive these signals. However, during use, the user mayalso receive extraneous electromagnetic signals from the surroundingenvironment, and these received signals may be inadvertently transmittedto the receiving antenna in the stylus 200 and can interfere withdesired signals. However, when the user is in contact with theconductive grip 132, any electromagnetic signals passing through theuser are sent to ground. They do not interfere with signals that areeventually sent through the stylus 200 to the signal processingelectronics.

FIG. 2( a) is an exploded view of some components of a stylus 200according to an embodiment of the invention. Stylus housing 132 includestwo housing portions 132(b)′, 132(b)″ with two corresponding conductivegrip portions 132(a)′, 132(a)″ that will eventually form the conductivegrip 132. A ring 152 and a nose 154 at the distal end 200(a) of thestylus 200 secure the parts of the stylus 200 at the distal end 200(a)together. A cap 910 is at the proximal end region 200(b) of the stylusand supports the strain relief element 142(a) and the threaded cap 144.

A writing element 130 in the form of a mechanical pencil is present inthe housing 132. The writing element 130 has a first end portion 138(a)proximate to the distal end region 200(a) of the stylus 200. A secondend portion 138(b) of the writing element 130 is proximate to theproximal end region 200(b) of the stylus 200.

The writing element 130 also includes a slide member 130(a) at the firstend portion 138(a) of the writing element 130. When the slide member130(a) is pushed upward by the downward motion of the writing element130 onto a writing surface, the pencil lead (not shown in FIG. 2( a))inside of the writing element 130 automatically feeds outward anddownward toward the writing surface.

It is desirable to use a writing element 130 with an automatic leadfeeding mechanism. Because the writing element 130 is present in thestylus housing 132, it is difficult for a user to directly manipulatethe writing element 130 to cause, for example, pencil lead to come outof the writing element 130. Since the lead automatically feeds to theappropriate length for writing, the user need not worry about feedingtoo much or too little lead. Also, if the electrographic positionlocation apparatus is to be used by children, pencil leads that extendtoo far out of the stylus can break. This can frustrate children. When awriting element 130 of the type shown in FIG. 2( a) is used, the slidemember 130(a) protects the pencil lead inside of it from breaking. Thelead is automatically fed just to the tip of the slide member 130(a) anddoes not extend too far outward. Accordingly, when using the stylus 200,the user need not worry about breaking pencil lead. A more detaileddiscussion of the writing element 130 is provided below.

A threaded cap 144 including a first end section 144(a), a middlegrooved section 144(b), and a second end section 144(c) is at theproximal end portion 200(b) of the stylus 200. The first end section144(a) of the threaded cap 144 inserts into the second end portion138(b) of the writing element 130. The grooves at the middle groovedsection 144(b) may engage grooves 166 at an end portion of the stylushousing 132 so that the threaded cap 144 is secured to the writingelement 130.

When the stylus 200 is fully assembled, the user may manipulate (e.g.,turn) the second end section 144(c) of the threaded cap 144 to (i)extend the writing element, (ii) retract the writing element 130, and/or(iii) remove the writing element 130 from the housing 132. The user maywant to remove the writing element 130 from the stylus housing 132 toreplace it or re-supply it with an appropriate writing material (e.g., anew pencil lead).

A detent member 146 with three adjustable positions fits within thethreaded cap 144 and has a structure that allows the treaded cap 144 tobe re-positioned. The detent member 144 has lateral projections thatextend laterally past the threaded cap 144 to engage grooves at theinner surface of the stylus housing 132.

The strain relief element 142(a) is connected to a coaxial cable 142,which passes through the housing 132 and runs parallel to the writingelement 130. The coaxial cable 142 includes an inner conductor that iselectrically coupled to the conductive cone 150, and an outer conductorthat is electrically coupled to the conductive grip 132. The inner andouter conductors may be electrically isolated from each other. Together,the inner conductor in the coaxial cable 142 and the conductive cone 150can form a receiving antenna, which can receive an electromagneticsignal and transmit it to the appropriate signal processing electronicsin the electrographic position location apparatus. At least part of thefirst end portion 138(a) of the writing element 130 passes through aconductive cone 150 at the distal end of the stylus 200.

FIG. 2( b) shows the combination of the writing element 130 and thethreaded cap 144. The combination shown in FIG. 2( b) is insertable inthe stylus housing 132. When the user turns the writing element 130, theentire writing element 130 may be withdrawn into the stylus housing 132(as opposed, for example, to withdrawing only the lead of the writingelement 130). A user may separate the threaded cap 144 from the writingelement 130 in order to fill the writing element 130 with lead.

FIG. 2( c) shows a cross-sectional view of the stylus 200 when all ofits components are assembled together. The description of the stylus 200above with respect to FIGS. 2( a) and 2(b) also applies to FIG. 2( c).

In addition, FIG. 2( c) shows some more details of some other features.For example, FIG. 2( c) shows an external ground shield 805 at theproximal end 200(a) of the stylus 200. The external ground shield 805can be formed by a conductive paint (e.g., silver paint). An internalground shield contact structure 815 (shown by dotted lines) electricallycouples the conductive grip 132(a) and the ground shield 805 to agrounded conductor in the cable 142. The grounded conductor (not shownin FIG. 2( c)) in the cable 142 may be a sheath-type conductor thatshields an inner signal transmitting conductor.

In FIG. 2( c), the lateral projections of the detent member 146 can alsobe seen. These lateral projections extend laterally past the threadedcap 144 and engage the inner surface of the stylus housing 132.

FIG. 2( c) also shows some additional details of the writing element130. The writing element 130 includes a slide member 130(a) at a firstend portion 130(a) of the writing element 130. The slide member 130(a)houses a pencil lead 808 (which may be colored, black, and optionallynon-conductive). A retainer ring 809 is under a compression spring 811,which is disposed around a clip member 812. A stainless steel ball 813is adjacent to the clip member 812. A clamp structure 814 is around theclip member 812. A pencil lead support 817 supports pencil lead 808. Apencil plug 819 is in the middle of the writing element 138. Theoperation of a writing element 130 of the type shown in FIG. 2( c) willbe described below with reference to FIG. 3.

Referring to FIG. 3, the writing element 130 has a tip cover 909 havinga smooth outer inclined surface 902, a connecting barrel 919 formed onthe tip cover 909 and fitted in a barrel (not shown), a slide member138(a) slidably mounted in the tip cover 909, a pencil lead 808, aretaining ring 809 for retaining the pencil lead 808, and a clip member812 that defines a holding portion for holding the pencil lead 808. Theclip member 812 has two sides each defining a recess 952 for receiving aball 813. A clamp structure 814 is mounted around the clip member 812,and a spring 811 is mounted between the clip member 812 and the slidemember 138(a).

In use, the pencil lead 808 is pushed outward automatically by theupward pressure on the slide member 138(a) that is exerted by a writingsurface such as paper (not shown). The outward advancement of the pencillead 808 occurs without any intentional manipulation of a lead feedingbutton by the user. The spring 811 compresses and this causes the clipmember 812 to open and release the pencil lead 808. Further detailsabout the automatic pencil shown in FIG. 3 can be found in U.S. Pat. No.6,254,296, which is herein incorporated by reference in its entirety forall purposes.

FIG. 4 shows a cross-section of a stylus 360 according to anotherembodiment of the invention. Like the stylus shown in FIG. 1, the stylus360 shown in FIG. 4 includes a proximal end region 350 and a distal endregion 352. A cable 338 is coupled to the proximal end region 338 of thestylus 360, and passes through a strain relief element 318 that is atthe proximal end region 338.

The stylus 360 includes a writing element 326 that is an ink pen refill.In this example, the writing element 326 is shown in an extendedposition, because the tip 336 of the writing element 326 is capable ofwriting. The ink pen refill can comprise a conductive material such asaluminum. The ink pen refill can comprise an erasable or non-erasableink material.

The distal end region 352 of the stylus 360 includes a front barrelhousing portion 302, while the proximal end region 350 of the stylus 360includes a rear barrel housing portion 320. The rear barrel housingportion 320 houses a rear inner barrel portion 316 that houses the cable338. The front barrel housing portion 302 and the rear barrel housingportion 320 can rotate with respect to each other in order to cause thefirst and second cam members 310, 312 to interact. This interactionbetween the first and second cam members 310, 312 causes the writingelement 326 to be in an extended position or a retracted position. Thecam members 310, 312, are described in further detail below.

A spring 328 is around the writing element 326. In the absence of abiasing force, the spring 328 biases the writing element 326 into aretracted position. The first and second cam members 310, 312 can rotatewith respect to each other and can apply an outward force to the writingelement 326 to push it outward into an extended position. The writingelement 326 is also releasably secured in the front barrel housingportion 302 with a front bushing 330 so that the writing element 326 isproperly positioned in the stylus housing 132.

A conductive cone 332 is at the distal end 352 of the stylus 360. Thewriting element 326 and the conductive cone 332 can form an antenna(e.g., a receiving antenna) in this embodiment. Unlike the embodimentshown in FIGS. 1 and 2, the writing element 326 in this embodiment canreceive a signal, transmit a signal to signal processing electronics,and provide a writing function.

In some embodiments, the conductive cone can be a “floating” conductivecone 332. That is, the writing element 326 may not be in physicalcontact with the conductive cone 332, or the writing element 326 is incontact with the conductive cone 332, but is movable with respect to theconductive cone 332. In either case, electromagnetic signals can bereceived by the conductive cone 332 and can be transmitted to thewriting element 326, even though a permanent mechanical connection isnot present, because they are very close to each other in someembodiments. In this sense, the conductive cone 332 and the writingelement 326 can be electrically or capacitively coupled together. Thus,the conductive cone 332 and the writing element 326 may be mechanicallyseparated from each other, but may also be in electrical communicationwith each other. In other embodiments, it is possible to electricallyconnect the conductive cone 332 to the writing element 326 with aflexible conductor or other means so that the writing element 326 maymove with respect to the conductive cone 332, and may also be bothmechanically and electrically connected.

A conductive grip 306 is on the front barrel housing portion 302. Theconductive grip 306 is electrically coupled to a first ground shield 308via a ground connector 304. The first ground shield 308 is connected toa second ground shield 314, which is in the rear barrel housing portion320. The conductive grip 306 grounds the user when the user contacts thestylus 360 so that signals received by the user do not pass to theconductive writing element 326. A protruding structure 382 is providedat the distal end 352 of the stylus 360. The protruding structure 382keeps the user's hand on the conductive grip 306 so that the user isgrounded.

FIG. 5 shows the stylus 360 shown in FIG. 4 in a retracted position.That is, the tip 336 of the writing element 326 is within the frontbarrel housing portion 302 and cannot be used to write on the surface ofa sheet.

FIGS. 6( a) and 6(b) show how the first and second cam members 310, 312interact with each other. Referring to FIG. 6( a), the first and secondcam members 310, 312 have inward ends that face each other andcooperatively fit together so that the writing element 326 is in aretracted position. Referring to FIG. 6( b), the facing ends of thefirst and second cam members 310, 312 push away from each other. Thefirst cam member 310 pushes the writing element 326 (see FIG. 4) outwardso that it is in an extended position and is moved by a distance A.

FIG. 7 shows how a stylus 360 can be used to both write and receive anelectromagnetic signal from under a surface of a housing in anelectrographic position location apparatus. In FIG. 7, like elements inthe stylus 360 are designated by like numerals as in prior Figures.

The stylus 360 is shown resting on the surface of the page of a book 4that lies within the recess in the upper section 10 of a housing 222.The upper section 10 includes an upper surface 10(a). Immediatelybeneath the upper section 10 of the housing 222, lies the conductivefingers 85 of an upper antenna 80. These conductive fingers 85 areprovided above an acetate insulating sheet 83 that separates the upperantenna 80 from a lower antenna 82. Disposed on the opposite side of theacetate sheet 83 are the conductive fingers 87 of the lower antenna 82.Beneath the lower antenna 82 lies the protective sheet of a card 70 thatis supported by supports 74 of the lower section 12 of the housing 222.

The distal end region 352 of the stylus 360 includes the conductive cone322 and the conductive tip 336 of the writing element 326. The writingelement 326 and the conductive cone 322 may function as a receivingantenna that receives electromagnetic signals from the fingers 85, 87 ofthe first and second antennas 80, 82 and are thus in electricalcommunication with each other. The signals are sent to a processor (notshown in FIG. 7) coupled to the writing element 326, and the processordetermines the x-y coordinates (over the upper surface 10(a)) of thewriting element 326 and/or the particular signals being transmitted bythe fingers 85, 87. Once the location of the stylus 360 is known, anoutput (e.g., an audio output) corresponding to a print element at thelocation of the stylus 360 and on the book 4 can be produced (since thecoordinates of the print element can be determined by the processor).

The user may interact with the book 4 when the writing element 326 is inan extended position or in a retracted position. That is, the user mayreceive some output corresponding to the particular location of thestylus 360 when the writing element 326 is in either an extendedposition or a retracted position. For example, different print elementsin a print medium on the housing can be selected using the stylus whenthe writing element in the stylus is in a retracted position or in anextended position. Different outputs can be produced for the differentprint elements, while the writing element in the stylus is in either aretracted position or an extended position. Illustratively, when thewriting element in the stylus is in a retracted position, the user mayselect an image of the letter “A” on a sheet of paper on a housing of anelectrographic position location apparatus. A first output related tothe letter A would then be produced by an appropriate output device(e.g., “A says Ahh”). The user may then manipulate the stylus to put thewriting element in an extended position. The user may then select orwrite on the letter “B” on the sheet of paper (or on another sheet) withthe stylus. A second output related to the letter B would then beproduced by the output device (e.g., “B says Buh”).

The advantages of using a conductive annular structure, or moreparticularly a conductive cone, at the distal end of the stylus can bedescribed with reference to FIGS. 8( a)–8(d). FIGS. 8( a)–8(b) showschematic illustrations of a stylus 602 including a conductor 602(a)with a writing element 602(b). The stylus 602 is coupled to a housing601 via a cable 604. A sheet 600 is on the surface of the housing 601. Aconductive finger 610 of a transmitting antenna is inside of the housing601. As shown, the distance (D1 and D2) between the end E of theconductor 602(a) and the conductive finger 610 is different depending onhow the stylus 600 is oriented when the user is writing. The signaltransmission distance from the conductive finger 610 to the receivingend E of the conductor 602(a) is also different in each case. Thedifferent signal transmission distances makes it difficult for theconductor 602(a) to receive signals of consistent magnitude.Electromagnetic signals that are transmitted from the conductive finger610 get weaker as the distance from the conductive finger 610 increases.

FIGS. 8( c) and 8(d) show how a conductive annular structure around thewriting element addresses this problem. FIGS. 8( c) and 8(d) are thesame as FIGS. 8( a) and 8(b), except that a conductive annular structure618 in the form of a conductive cone is present at the distal end of thestylus 602. The conductive annular structure 618 is electrically coupledto the conductor 602(a) and together they can form a receiving antenna.As is apparent from viewing FIGS. 8( c) and 8(d), the transmissiondistance from the transmitting finger 610 is substantially the same,regardless of the particular orientation of the stylus 602. Accordingly,signals of consistent strength can be received by the conductor 602(a),regardless of the particular orientation of the stylus. This makes theelectrographic position location apparatus more reliable.

FIG. 9 is an exploded view of an electrographic position locationapparatus including a platform unit. Platform units and other featuresare described in U.S. patent application Ser. No. 09/777,262, filed onFeb. 5, 2001, which is herein incorporated by reference in its entirety.

The electrographic position location apparatus shown in FIG. 9 includesa processor 60 that is connected to a loudspeaker 61, an ON/OFF button 5and a headphone jack 37. A cable 6 couples the processor 60 to a stylus3. The stylus 3 may be any of the above-described styluses. Theprocessor 60 is connected to a mating interface 62 for receiving acartridge 39 and a set of batteries 63 for powering the processor 60.

Two antenna elements 64, 66 are connected via cables 67 to the processor60 enabling the processor 60 to control the timing of signals generatedby the first transmitting antenna elements 64, 66. The antenna elements64, 66 are provided directly beneath rectangular recesses 20, 22. Theyare sandwiched between the underside of the upper sections 9, 10 of thefirst and second housings 1, 2 defining the rectangular recesses 20, 22and sheets of cardboard 68, 70. They rest upon supports 72, 74 on theinside surfaces of the lower sections 11, 12 of the first and secondhousing portions 1, 2.

Referring to FIG. 10, each antenna element 64, 66 comprises an upperantenna 80 and a lower antenna 82 separated by an insulating acetatesheet 83. The upper antenna 80 comprises a resistive strip 84 formed byprinted conductive ink, that extends along one of the short sides of arectangle corresponding to the area defined by the rectangular recess20, 22 beneath which the antenna element is located. Extending away fromthe resistive strip 84 at right angles to the resistive strip 84 is aplurality of conductive fingers 85 also comprising printed conductiveink. These conductive fingers 85 are spaced equidistantly from oneanother along the length of the resistive strip 84 and run parallel toone another. The conductive fingers 85 extend from the resistive stripto a length corresponding to the extent of the long side of therectangular recesses 20, 22.

The lower antenna 82 is disposed on the opposite side of the insulatingacetate sheet 83 and comprises a second resistive strip 86. This secondresistive strip 86 extends along the periphery of the area along thelong side defined by the rectangular recesses 20, 22 beneath which theantenna is located. In a similar arrangement to the arrangement of theupper antenna 80, extending away at right angles from the resistivestrip 86 of the lower antenna 82 are a plurality of conductive fingers87 spaced equidistant from one another along the length of theconductive strip 86. The number of conductive fingers 85, 87 can varydepending on the desired resolution.

The conductive fingers 85, 87 of the second antenna arrangement 66within the second housing portion 2 form an orthogonal lattice ofequally spaced conductive fingers 85, 87 that extends across theentirety of the area defined by the rectangular recess 22 in the uppersection 10 of the second housing portion 2 with conductive strips 84, 86extending beyond the periphery of this area. Similarly, the conductivefingers 85, 87 of the antenna element 64 within the first housingportion 1 define an orthogonal lattice of equally spaced conductivefingers 85, 87 extending beneath the extent of the rectangular recess 20in the upper section 11 of the first housing portion 1. These orthogonallattices of conductive fingers 85, 87 are used to generateelectromagnetic fields in the vicinity of the surface of the recesses20, 22 which can be detected by the stylus 3. They are used to determinewhich portions of a two-dimensional book in the rectangular recesses 20,22 have been selected with the stylus 3.

Provided at either end of the resistive strip 84 of the upper antenna 80are first 93 and second 94 electrical contacts that are connected viaconductive wiring 95 to an interface 96 and hence via the cable 67 tothe processor 60. Similar first 97 and second 98 electrical contacts areprovided at either end of the resistive strip 86 of the lower antenna82. These contacts 97, 98 are also connected via conductive wiring 99 tothe interface 96, hence via the cable 67 to the processor 60. As in thecase of the upper 80 and lower 82 antennas these electrical contacts 93,94, 97, 98 and the conductive wiring 95, 99 also comprise conductive inkprinted on the surface of the acetate sheet 83.

The electrical contacts 93, 94, 97, 98 and conductive wiring 95, 99enable electrical signals to be applied to the resistive strips 84, 86.When alternating signals are applied to the resistive strips 84, 86, theconductive fingers 85, 87 connected to the resistive strips 84, 85 togenerate an alternating electromagnetic field, which can be detected bythe stylus 3. The resistive strips 84, 86 may comprise a voltage dividerstrip that allows signals of different voltages to transmit from each ofthe conductive fingers 85, 87. Further details about the voltage dividerstrip are described in U.S. patent application Ser. No. 09/574,499,filed May 19, 2000. In this U.S. patent application, the voltage dividerstrip includes a number of resistors in series. These resistors allowthe conductive fingers 85, 87 to transmit signals of different voltages.Of course, other types of antenna systems may be used. For example,other embodiments that use capacitive division are described in U.S.patent application Ser. No. 10/222,205, filed on Aug. 16, 2002. Both ofthese applications are assigned to the same assignee as the presentapplication and are herein incorporated by reference for all purposes.

FIG. 11 is a schematic block diagram of the processor 60 and the antennaelements 64, 66. The processor 60 comprises a controller unit 120,transmitter logic 121 and a receiver unit 122. The processor 60 mayinclude a signal driver and a signal processor. The controller unit 120is connected via the transmitter logic 121 to the antenna elements 64,66. The controller unit 120 is also connected via the receiver unit 122via the cable 6 to the stylus 3. The transmitter logic 121 and receiverunit 122 are also connected to each other directly. The controller unit120 is also connected to the headphone jack 37, the loudspeaker 61, thecartridge mating interface 62 and the ON/OFF button 5.

When the ON/OFF button 5 is pressed, this is detected by the controllerunit 120 which causes the transmitter logic 121 to be activated. Thetransmitter logic 121 then applies electric signals to the electricalcontacts 93, 94, 97, 98 of the antenna elements 64, 66 in a sequence offrames. In these frames, each lasting approximately 3 milliseconds,predetermined electrical signals are applied to the contacts 93, 94, 97,98 of the transmitting antenna arrangements 62, 64. At the end of eachframe a different set of signals are then applied to the contacts 93,94, 97, 98.

In the course of a frame, an electromagnetic field is generated in thevicinity of the rectangular recesses 20, 22 in the upper sections 9, 10in the first and second housing portions 1, 2. These electromagneticfields induce voltage potentials in the conductive annular structure atthe distal end of the stylus 3. This signal is then passed via the cable6 to the receiver unit 122. In one example, the voltages applied to thecontacts 93, 94, 97, 98 may range between plus three volts and minusthree volts. The voltage induced within the conductive annular structurein the stylus 3 can be about 0.5 millivolts. The receiver unit 122 thenprocesses the induced voltage and a processed signal is then passed tothe controller unit 120.

The controller unit 120 then converts the processed signals receivedfrom the receiver unit 122 into signals identifying the coordinates ofthe portion of the page of the book 4 at which the stylus 3 is currentlylocated. These coordinates are then used to select an appropriate soundstored within a sound memory either provided as part of the controllerunit 120 or alternatively a sound memory provided as a memory chipwithin a cartridge inserted within the cartridge interface 62. Theappropriate sound is then output via the loudspeaker 61 or to a set ofheadphones via the headphone jack 37.

All of the above patents and patent applications are herein incorporatedby reference in their entirety for all purposes. None of the citedpatents and patent applications is admitted to be prior art.

Those skilled in the art will appreciate that various adaptations andmodifications of the above-described embodiments can be configuredwithout departing from the scope and spirit of the inventions.Therefore, it is to be understood that, within the scope of the appendedclaims, the invention may be practiced other than as specificallydescribed herein. Moreover, one or more features of an embodiment of theinvention may be combined with any other feature of any other embodimentof the invention without departing from the spirit and scope of theinvention.

1. A method comprising: writing on a sheet using an electronic stylusincluding a retractable writing element, wherein the writing element isin an extended position; receiving a first audio output after writing onthe sheet; retracting the writing element into the stylus; selecting aprint element on the sheet or another sheet using the stylus when thewriting element in the stylus is in a retracted position; and receivinga second audio output after selecting the print element.
 2. The methodof claim 1 wherein the sheet is in a book.
 3. The method of claim 1wherein the writing element is a lead pencil including an automatic leadfeeding mechanism.
 4. The method of claim 1 wherein the writing elementcomprises ink.
 5. The method of claim 1 wherein the sheet is a printmedium that is adapted to teach math.
 6. The method of claim 1 whereinthe writing element comprises a pencil including an automatic leadfeeding mechanism.
 7. The method of claim 1 wherein the sheet is adaptedto teach writing, math or reading.
 8. The method of claim 1 wherein theelectronic stylus includes a wire operatively coupled to a controller.9. An assembly comprising: an electronic stylus comprising a distal endregion, a proximal end region, and a retractable writing element havinga first end portion and a second end portion; and an audio outputdevice, wherein the audio output device provides a first audio outputwhen the writing element is used to write on a sheet and is in anextended position and wherein the audio output device provides a secondaudio output when the writing element is in a retracted position and isused to select a print element on the sheet or another sheet.
 10. Theassembly of claim 9 wherein the retractable writing element compriseslead.
 11. The assembly of claim 9 wherein the retractable writingelement comprises ink.
 12. The assembly of claim 9 wherein the sheet isadapted to teach math or reading.
 13. The assembly of claim 9 whereinthe audio output device is a speaker.
 14. The assembly of claim 9wherein the sheet is part of a book.
 15. The assembly of claim 9 whereinthe first and second audio outputs provide feedback to a user inresponse to writing on the sheet or selecting the print element.
 16. Asystem comprising: the assembly of claim 9; and the sheet.
 17. Theassembly of claim 9 wherein the electronic stylus includes a wireoperatively coupled to a controller.